Coating compositions having high weathering resistance, process for preparation thereof and use thereof

摘要

What are described are coating compositions comprising pigments and/or fillers and multistage polyvinyl ester dispersions as binders. These binders are produced by a selected multistage process in which a polyvinyl ester dispersion is obtained in a first stage, monomers in dissolved or pure form or in the form of an emulsion are added to the reaction mixture in a second stage and then the polymerization is started again. The polyvinyl ester dispersions comprise polymerized silanes and/or epoxides or the polyvinyl ester dispersions have only a small content of protective colloids, if any. The coating compositions formulated with the multistage polyvinyl ester dispersions obtained in this way are notable for a very high weathering resistance.

主权项

1. A coating composition comprising a multistage polyvinyl ester dispersion, wherein the multistage polyvinyl ester dispersion is produced by a method comprising
i) polymerizing in a first stage a polymerization mixture comprising at least one vinyl ester of a saturated carboxylic acid and optionally further monomers copolymerizable therewith in the presence of at least one emulsifier up to a conversion of at least 90% of the monomers used, ii) adding in a second stage to the polymerization mixture obtained in the first stage at least one free-radically polymerizable monomer other than the vinyl ester used in the first stage the at least one free-radically polymerizable monomer selected from the group consisting of an acrylate, a methacrylate, an acrylamide, a methacrylamide, a diester of maleic acid with a C1-C18 alcohol, a diester of fumaric acid with a C1-C18 alcohol, and a vinylaromatic, with the proviso that a vinyl ester of a carboxylic acid is not added in the second stage with the at least one free-radically polymerizable monomer, wherein the at least one free-radically polymerizable monomer is added in pure form, in the form of a solution or in the form of an emulsion, and with the proviso that the at least one free-radically polymerizable monomer is added at a temperature that is lower than the temperature of the polymerization mixture at the end of the first stage, iii) adding in a third stage after termination of the second stage at least one free-radical polymerization initiator, and iv) adding a pigment, a filler, or a combination thereof, wherein v) the coating composition does not contain a protective colloid, and vi) the coating composition does not include hydraulically setting materials.